Norman Lamps, Inc.

PS-type bulbs feature an elongated, pear-shaped envelope that's larger and more rounded than standard A-shape bulbs, creating a distinctive appearance while providing high light output in both utilitarian and decorative applications. The "PS" designation stands for "pear straight" – the bulb has a pear-like rounded top that transitions to straight sides before narrowing to the base. These bulbs are particularly common in high-wattage applications, commercial and industrial settings, and decorative fixtures where the larger bulb size is either necessary for technical reasons or desirable for aesthetic effect.

Size designations follow the standard system: a number indicating the diameter in eighths of an inch. PS25 bulbs are 25/8 inches (3.125") in diameter, PS30 bulbs are 3.75" in diameter, and PS35 bulbs are approximately 4.375" in diameter. The larger envelope sizes allow for higher wattage bulbs (150W, 200W, 300W) because the increased surface area helps dissipate heat and prevents excessive glass temperatures that would shorten bulb life or pose safety concerns.

High-wattage incandescent PS bulbs have been largely phased out due to energy efficiency regulations, but specialty versions remain available for applications exempt from these regulations. These include rough service PS bulbs with reinforced filaments for high-vibration environments, shatter-resistant versions with safety coatings for food service and industrial applications, and three-way PS bulbs (common wattages like 50/100/150W or 100/200/300W) for table lamps and floor lamps with three-way sockets.

Three-way PS bulbs deserve special mention as they're one of the most common reasons someone specifically needs a PS bulb. Three-way lamps use special sockets with three contacts that allow switching between low wattage (one filament), medium wattage (second filament), and high wattage (both filaments). A typical three-way PS25 or PS30 bulb might be 50/100/150W, providing low light for ambiance, medium light for general use, and high light for reading or tasks. The PS shape accommodates the two filaments and provides adequate surface area for heat dissipation at the high setting.

LED PS bulbs have become excellent alternatives for most applications, offering 80-90% energy savings and 15,000-25,000 hour lifespans. LED three-way PS bulbs replicate the three-way functionality using electronics to switch between different LED output levels when used in three-way sockets. A 10/20/30W LED three-way bulb provides light equivalent to a 50/100/150W incandescent while using a fraction of the energy and generating far less heat. The PS shape is maintained for compatibility with fixtures designed for PS bulbs and for the aesthetic effect in open fixtures.

Base types on PS bulbs are typically medium (E26) for smaller wattages and lower wattages, and mogul (E39) for high-wattage versions (200W+). The mogul base is larger and more robust, designed to handle the higher currents that high-wattage bulbs draw. This means a high-wattage PS bulb with mogul base won't fit in a standard medium-base socket – you need fixtures specifically designed with mogul sockets.

Decorative applications use PS bulbs in open fixtures where the distinctive bulb shape contributes to the overall aesthetic. Some pendant lights, industrial-style fixtures, and statement lamps use exposed PS bulbs as a design element. Clear glass PS bulbs show the visible filament arrangement, while frosted versions provide softer light without glare. LED filament PS bulbs now offer the vintage look of exposed filaments with modern LED efficiency.

Common Sizes: PS25 (3.125" diameter), PS30 (3.75"), PS35 (4.375"), PS40 (5"), PS52 (6.5")

Base Types: Medium (E26) for lower wattages, mogul (E39) for high-wattage versions

Common Types: Three-way (most common - 50/100/150W equivalent), rough service, shatter-resistant, standard single wattage, decorative LED filament

Applications: Three-way table lamps and floor lamps, high-wattage industrial fixtures, commercial lighting, decorative fixtures, rough service environments